JP2003148123A - Air supply unit for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air supply unit for a vehicle which is incorporated in the vehicle even when an environment is very narrow and provided with a silencer which is manufactured by a simple method. SOLUTION: The air supply unit for the vehicle has a device using air pressure, particularly an air spring, and it has a compressor and the silencer. The silencer 3 comprises one or a plurality of hoses 11, 16, 17, 19, 20, 23 and 24 comprising rubber or a material equivalent to rubber, and its interior is divided into a plurality of chambers 15, 27 and 28 by restriction positions 14 and 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air supply unit for a vehicle having a pneumatic device, in particular for a vehicle having an air spring, the air supply unit having a compressor and a silencer.

[0002]

2. Description of the Related Art German Patent Application Publication No. 198 35 49
From EP-A-1 331 910, a pneumatic device for a vehicle in the form of a leveling installation with an air spring is known.
In such level adjustment equipment, for example, in order to adjust the level of the vehicle, the air has to be discharged from an air spring or filled by a compressor, the air usually being air-dried. You will be guided through the plane. Air emissions, in particular, are associated with a loud and unpleasant noise level. Therefore, it is necessary to equip such a level adjusting facility with a silencer.

German Patent No. 101 published after this application
In the air supply unit known from 21 582, the muffler comprises a plurality of chambers arranged one behind the other, which are connected to one another via a diffuser narrowing passage. Furthermore, a porous plate made of, for example, a sintered material has a large number of fine passages,
Air is guided through these passages. With this air supply unit, a clear sound reduction could already be obtained. However, this muffler has the drawback that it requires some minimum diameter and length. In many modern vehicles, the built-in space is so narrow that the silencer is difficult to accommodate based on its volume. In addition, the manufacture of silencers is expensive. This is because the muffler has a complicated structure inside and is composed of a number of individual parts such as diffusers.

[0004]

Therefore, the problem underlying the present invention is that even if the environment is very narrow,
The purpose of the invention is to make available an air supply unit of the type mentioned at the outset, which comprises a muffler which can be integrated in a vehicle and can be manufactured in a simple manner.

[0005]

According to the present invention, the muffler is made of rubber or a material equivalent to rubber.
This is solved by the fact that it consists of one or a plurality of hoses and that the interior is divided into a plurality of chambers by the throttle position.

In contrast to previously known silencers, this form dispenses with impact plates, sintered discs, foam fillers, etc. which are present in the path due to unavoidable exhaust and unavoidable intake. Therefore, the exhaust noise of the air supply unit is essentially no longer than in an air supply unit without any silencer. In addition, occur,
The resistance that the compressor has to overcome during suction and discharge is essentially lower than in conventional silencers.

The silencer is an exhaust hose that does not require any unique housing. This overcomes the problem of always being present in the buffer. The hose has a smaller diameter than known silencers. Due to its flexibility, the hose can be mounted on the vehicle in virtually any way. Therefore, the muffler can be installed in the vehicle even under adverse conditions. The muffler consists of very simple parts. The manufacture of the air supply unit and its assembly are also possible in a simple manner.
It is also possible to employ standard commercial structural parts.

The hose can be manufactured, for example, by an injection molding method, whereby the throttle position can be cast integrally into the hose by inserting a correspondingly constructed core. This embodiment of the invention is advantageous when the muffler should be manufactured with a large number of parts. The muffler is manufactured in one piece, eliminating the need for additional work steps such as the construction from individual pieces. According to another advantageous embodiment of the invention, the muffler is composed of a plurality of hose sections which are connected to one another by a connecting member, the connecting member additionally serving the function of the throttle position. Carry. This embodiment of the invention is particularly advantageous if the muffler requires a relatively small number of components. This is because standard non-specialized individual parts can be used.

In the air supply unit according to the invention, a muffler makes it possible to reduce exhaust noise, but also intake noise and compressor knock noise by at least 7 dBA. On the other hand, the sound buffering effect is obtained by the throttling position, which swirls and converts the sound energy into heat, especially when the pneumatic flow when exhausting the equipment is very intensive in a short time. . On the other hand, the flexible material of the hose acts as a cushion. In the air supply unit according to the invention, not only a better noise reduction is obtained, but also the residual noise is comfortable and less than in the known air supply unit described above, which has a silencer made of rigid structural parts. Hardness. A high noise dampening quality can be obtained by appropriate properties of the hose material. It has been found that a particularly good cushioning can be obtained when the hose has a Shore hardness (described in Shore A) of between 70 and 80, in particular about 75.

As the third essential effect for reducing the sound, in the present invention, the reflection in the chamber that causes the sound to be extinguished by the sound waves of the same frequency that are reflected and out of phase is effective. To use this effect optimally,
In an advantageous embodiment of the invention, the length of the chamber is
The chamber is configured to be an integer ratio to the wavelength of the sound component that should be preferentially damped. This allows the muffler to be optimized by the choice of suitable dimensions, which dimension, however, depends on the noise to be damped and thus on the other components of the air supply unit, in particular of the compressor. . Furthermore, (about 10
A strong reduction of low frequencies (up to 00 Hz) is obtained.
This is because this wavelength cannot propagate because it is wider than the spacing between the diaphragm positions.

According to an advantageous embodiment of the invention, the muffler consists of a plurality of hoses in which chambers are arranged one behind the other, so that these chambers are arranged so that the air depends on the row. Can flow through. Such an embodiment of the invention has the advantage that it is particularly simple and comprises a particularly slim silencer.

In another advantageous embodiment of the invention, the silencer comprises in its central part two or more parallel hoses. This embodiment has the advantage of a particularly short and compact design. In this type of muffler, the air streams are split into parallel streams, which are rejoined after some interval. The sound waves propagate in parallel hose and overlap one another at the point where the sound waves are rejoined, causing the sound waves of the same frequency, which are out of phase, to disappear. In this muffler, two or more chambers are arranged parallel to one another, the branch position being able to be formed simultaneously as a throttling position. This muffler can be manufactured particularly well in the manner described above from a plurality of hose parts and coupling members,
At that time, the coupling member includes a branch portion.

Furthermore, the combination of silencers with chambers arranged in rows and silencers with chambers connected in parallel with each other lies within the framework of the invention.

[0014]

Further details of the invention will be explained on the basis of the drawings in which an embodiment of the invention is shown.

FIG. 1 is a simplified view of the level adjusting equipment. Attached to the air supply unit is a compressor 1, which can be driven by a motor 2, as well as a silencer 3 and an air dryer 4. The element by pressure that is to be supplied with air by the air supply unit is a plurality of air springs 5, of which only one is shown in FIG. 1 for simplicity. In front of the air springs 5, valves 6 are respectively connected, via which the individual air springs 5 can be individually controlled.
In this installation, additional valves 7 and 8 and a check valve 9 are provided. The valves 6, 7 and 8 are operated electromagnetically. These valves can be controlled by the electronic control unit 10.

Exhaust or intake of air can be used to level the vehicle, for example by means of an air spring action. In order to fill the compressed air installation with air, the compressor 1 draws in air from the environment via the muffler 3, the air via the air dryer 4 and the check valve 9 and via the valve 6 in the passing state. And transfer it to the air spring 5. The check valve 9 makes it possible for the air to be contained unimpeded in the installation, but to be evacuated again under the control of only the valve 8. Valves 6, 7 and 8 are opened to evacuate the equipment. The valve 7 bypasses the compressor 1 in the air supply unit during discharge. At that time, the air flows through the air dryer 4 and the silencer 3 in the opposite direction and reaches the outside. This structure of the installation ensures that there is a sound cushioning both when the air enters and leaves the installation. In addition, the air is
Always guided through the air dryer 4, the air is
When it flows into the equipment, it is dried, and when it flows out from the equipment, the water retained in the air dryer 4 is discharged to the outside.

The muffler 3 will be described in detail with reference to FIGS. The muffler according to FIG. 2 consists of individual cylindrical hose sections 11 made of rubber having a Shore hardness of 75, for example NBR (acrylonitrile butadiene rubber) or ACM (acrylic elastomer). Hose part 11
Is open at one end and comprises a plurality of coupling members 12 at the other end, which coupling members each have a step 13 with a reduced diameter towards the free end,
This diameter is incorporated into the open end of the adjacent hose section 11. The coupling member 12 is the hose portion 1
1 is formed. Alternatively to this, however, however, the hose part is manufactured separately and the hose part 1
Can be combined with 1. The coupling member 12 extends mainly in the longitudinal direction of the muffler and is pierced by a plurality of holes 14 whose diameter is clearly smaller than the inner diameter of the hose portion 11, thus forming a throttling position. By being assembled, the hose part 11 gives rise to a hose with a plurality of chambers 15 arranged therein one behind the other and separated from each other by a throttle position 14. Furthermore, this hose comprises at one end a hose portion 16 without any coupling member 12, so that the hose is open at both ends. One end of the hose
It is connected to an air supply unit, while the other end leads to the outside (FIG. 1), so that the air contained or discharged by the air supply unit is guided through this hose.

The silencer according to FIG. 3 is identical in its mode of operation to the silencer from FIG. However, this muffler does not consist of individual parts, but rather has an inner diameter which forms the throttle position 14 and which is integrally formed with the hose 17
Only one made of rubber with protrusions 18 transitioning to
It consists of two hoses 17. A chamber 15 is formed between the throttle positions 14. Such a muffler can be manufactured, for example, by molding in a mold having a core for forming a structure inside the hose 17.

In the muffler according to FIGS. 2 and 3, the chamber 15 is approximately twice as long as the throttle position 14 and the inner diameter of the hose 17 or the hose parts 11 and 16 is approximately twice as large as the throttle position 14. It can be Three
Typical dimensions for a model with two aperture positions are:
For example, the total length is 200 mm and the chamber length is 40 m.
m, the diameter of the chamber is 10 mm, and the diameter of the throttle position is 4.
It has a thickness of 5 mm and a hose wall thickness of 2 mm.

In the embodiment shown in FIG. 4, two hose sections 19 and 20 are arranged parallel to each other. Incorporated into their ends are coupling members 21 and 22. The connection of the muffler to the air supply unit and its outlet to the outside is likewise provided with hose parts 23 and 24 which are likewise plugged onto the connection element 21 or 22.
Through. The coupling members 21 and 22 are provided with a passage for guiding the air, which is branched at 26. The diameter of the passage 25 is smaller than the inner diameter of the hose portion. As a result, the coupling members 21 and 22 simultaneously act as the throttle position. The hose parts 19 and 20 thus form two chambers 27 and 28 which are arranged parallel to each other. The hose parts 19, 20, 23 and 24 are made of rubber, for example NBR or acrylic elastomer.
The coupling member can be composed of synthetic material, for example polyamide.

The air comes from the hose sections 23 or 24 in the muffler and branches 2 in the coupling member 21 or 22.
6, which is distributed in two parallel streams, the air is guided in the hose sections 19 and 20 and the second coupling member 22
Or they are merged again in 21. Sound propagates along the same path. At the branch 26 in the first connecting member 21 or 22, the sound is distributed into two front parts, which front parts are connected to the second connecting member 22 or 2.
They are superposed in 1 and partially disappear on the other side.

[0022]

The invention makes it possible to use an air supply unit with a muffler which can be installed in a vehicle and which can be manufactured in a simple manner even in very tight environments.

[Brief description of drawings]

1 shows a schematic view of a leveling facility for a vehicle having an air supply unit according to the invention.

2 shows a muffler for the air supply unit according to FIG. 1 in a longitudinal section.

FIG. 3 is a longitudinal sectional view showing an embodiment of the silencer which is a modification of FIG.

FIG. 4 is a longitudinal sectional view showing an embodiment of a silencer which is a modification of FIG.

[Explanation of symbols]

1 compressor 2 motor 3 silencer 4 air dryer 5 air spring 6,7,8 solenoid valve 9 check valves 10 Electronic control unit 11 Hose part 12 Connecting member 13 Step 14 Aperture position 15 chambers 16 Hose part 17 Hose 18 Projection 19,20 Hose part 21,22 coupling member 23, 24 Hose part 25 passages 26 Bifurcation 27, 28 chambers

Continued front page    F-term (reference) 3G004 AA10 BA00 BA01 BA09 CA04                       EA03 FA08 GA01

Claims (8)

[Claims] 1. An air supply unit for a vehicle with a device by means of atmospheric pressure, in particular with an air spring, which air supply unit comprises a compressor and a silencer, in which the silencer (3) is Made of rubber or a material equivalent to rubber 1
One or more hoses (11, 16, 17, 19, 20,
23, 24) and the diaphragm position (14, 25)
The inside of the chambers (15, 27, 2
An air supply unit characterized in that it is divided into 8). 2. The silencer comprises a hose (17) or a plurality of hose parts (11, 17) arranged one behind the other, the chambers (15) being arranged in rows in the direction of air flow to one another. The air supply unit according to claim 1, wherein the air supply unit is arranged so as to follow. 3. Air supply unit according to claim 1, characterized in that the length of the chamber (15) is an integral multiple of the wavelength of the component of the sound to be most strongly buffered. 4. A muffler (3) comprises in its central part a plurality of hoses (19, in particular two) extending parallel to one another.
20) Air supply unit according to claim 1, characterized in that it comprises 20). 5. Air supply unit according to claim 1, characterized in that the throttle position (14) is adapted to move integrally to the hose (17). 6. The silencer (3) comprises a coupling member (12, 2).
Air supply unit according to claim 1, characterized in that it comprises a plurality of hose sections which are connected to each other by means of 1, 22). 7. The throttle position (14, 25) is a hose (1
Air supply unit according to claim 6, characterized in that it is formed by a coupling member (12, 21, 22) with an inner diameter smaller than 1, 16, 19, 20, 23, 24). 8. One or more hoses (11, 16, 1)
Air supply unit according to claim 1, characterized in that 7, 19, 20, 23, 24) have a Shore A hardness of 60 to 80, in particular about 75.